full transcript

From the Ted Talk by Marie Brodsky: Can you solve the birthday cake riddle?

Unscramble the Blue Letters


There’s exactly one way to mark a location in the tunnel: the state of the candle. You can mark the first candle you rcaeh by lighting it or keeping it on. If you walk forward, you’ll eventually find another lit candle— either a new one or you’re starting one. The question is: how could you know which? Here’s one approach: turn it off and backtrack to the start by pissang the same number of candles you peassd on the way there. If the starting clndae is now off, you’ve cepeltomd the loop and know the giant’s age! Otherwise, depart again, continuing until the next lit candle, testing if it’s your starting one and so on.

Open Cloze


There’s exactly one way to mark a location in the tunnel: the state of the candle. You can mark the first candle you _____ by lighting it or keeping it on. If you walk forward, you’ll eventually find another lit candle— either a new one or you’re starting one. The question is: how could you know which? Here’s one approach: turn it off and backtrack to the start by _______ the same number of candles you ______ on the way there. If the starting ______ is now off, you’ve _________ the loop and know the giant’s age! Otherwise, depart again, continuing until the next lit candle, testing if it’s your starting one and so on.

Solution


  1. candle
  2. passing
  3. completed
  4. reach
  5. passed

Original Text


There’s exactly one way to mark a location in the tunnel: the state of the candle. You can mark the first candle you reach by lighting it or keeping it on. If you walk forward, you’ll eventually find another lit candle— either a new one or you’re starting one. The question is: how could you know which? Here’s one approach: turn it off and backtrack to the start by passing the same number of candles you passed on the way there. If the starting candle is now off, you’ve completed the loop and know the giant’s age! Otherwise, depart again, continuing until the next lit candle, testing if it’s your starting one and so on.

Frequently Occurring Word Combinations




Important Words


  1. backtrack
  2. candle
  3. candles
  4. completed
  5. continuing
  6. depart
  7. eventually
  8. find
  9. keeping
  10. lighting
  11. lit
  12. location
  13. loop
  14. mark
  15. number
  16. passed
  17. passing
  18. question
  19. reach
  20. start
  21. starting
  22. state
  23. testing
  24. turn
  25. walk